1. Field of the Invention
The present invention relates to an exposure control apparatus of a camera having a plurality of exposure modes.
2. Description of Related Art
In a conventional camera having a plurality of exposure modes, a photographer can select a desired exposure mode by actuating an associated switch or button, etc.
In a recent camera having modes other than the exposure modes, such as a continuous shot mode, etc., the mode selection is effected by actuating a plurality of switches in combination.
However, ordinary photographers do not frequently use all of the exposure modes. Namely, only a few specific exposure modes are used. Therefore, for ordinary photographers, the need to actuate several switches in combination to select a mode is troublesome and complicated.
Furthermore, in a program exposure mode of a known camera, a shutter speed and a diaphragm value are automatically determined in a certain relationship (combination). Accordingly, it is impossible for the photographer to set optional shutter speed and diaphragm values which do not satisfy the predetermined relationship while in the same mode. For example, when an operation switch is actuated in a program exposure mode of a known camera, both the shutter speed and the diaphragm value are modified simultaneously while maintaining a specific relationship therebetween, and accordingly, it is impossible to vary only the shutter speed or diaphragm value. Consequently, if the photographer wants to vary only the shutter speed or diaphragm value while in the program exposure mode, it is necessary for the photographer to first switch the program exposure mode to a diaphragm priority automatic exposure mode or a shutter speed priority automatic exposure mode.
Furthermore, in a manual exposure mode of a known camera, the photographer manually sets the optimum shutter speed and diaphragm value, while observing an exposure meter provided in a field of view of a finder. Namely, since the photographer manually sets both the optimum shutter speed and diaphragm value by himself of herself, it is possible for him or her to create more artistic or technical pictures.
However, the adjustment of both the shutter speed and diaphragm value is troublesome, especially for the ordinary photographer. In particular, if one of either the shutter speed or diaphragm value is readjusted after the shutter speed and the diaphragm value are adjusted to obtain an optimum exposure value, the other of either the diaphragm value or shutter speed must also be readjusted to maintain the optimum exposure value, which changes as a result of the readjustment.